Like if you own a property your property papers shows its your property no one can claim that its his property not yours property cuz you are the one got papers , whats shows your authority on a domain name... i know the whois record got all the info about the domain owner but what is important thing in whois record that if you lose it you can lose your domain. email , home address or what is main thing...e.g if my email is hacked then can the hacker claim my domain name or if i move to the new house the people shifted in that house can they claim it???
When you buy a domain name, there are records showing you as the domain name owner. Just because someone impersonates you, it doesn't mean they can own your property. Just like your car, if someone claims to be you, that doesn't mean they can drive off with your car.
Only you can assign the domain name to an IP address. Only you can buy a SSL certificate for that domain name.
If they hack your email, they can request the registrar to change the IP address assigned to your domain name but that would set all kinds of red flags, such as why don't you do this yourself? Response emails will still go to your email address so they would have to be intercepted each time. Your DNS account should be password protected, as well as with two-factor authentication.
And when you wake up one morning to find your domain name not assigned to your IP, you call your registrar who will then verify your contact information and find out what's going on.